DocomintCalculadora de Gordura Corporal
Estime o percentual de gordura corporal a partir de medidas de fita métrica, com o método da Marinha dos EUA.
What is a Calculadora de Gordura Corporal?
The US Navy circumference method estimates body fat from a tape measure rather than a scale or scan — a more direct read on body composition than BMI, since it's based on where fat actually tends to accumulate rather than a weight-to-height ratio that can't tell fat from muscle.
How to use the Calculadora de Gordura Corporal
- Enter your gender, height, neck, waist, and (for women) hip circumference
- Press Calculate
- Your estimated body fat percentage appears instantly, computed on your device
Formula
Men: 495 ÷ (1.0324 − 0.19077×log₁₀(waist−neck) + 0.15456×log₁₀(height)) − 450 (US Navy method, cm)
Women's formula additionally factors in hip circumference, since fat distribution patterns differ by gender — the log-based structure comes from how the original Navy study statistically fit circumference measurements to body-fat outcomes.
Example
A man at 175cm with a 38cm neck and 85cm waist comes out to roughly 15.9% body fat — comfortably within the "fitness" range most standard body-fat charts define for men (14–17%).
Common mistakes
- Measuring circumferences loosely instead of snug against the skin — a loose tape measure understates body fat.
- Entering height in inches or feet instead of centimeters, which this tool expects.
- Expecting an exact match to a DEXA scan or hydrostatic weighing result — this is a field estimate, reasonably close but not clinically precise.
Frequently asked questions
How accurate is the US Navy body fat method?
It's a reasonable field estimate — typically within a few percentage points of more precise methods like DEXA scanning for most body types — but less accurate for very lean or very high body-fat individuals. It's popular because it only needs a tape measure, not specialized equipment.
Why do women need a hip measurement and men don't?
The US Navy formula's constants were derived separately for each gender based on typical fat distribution patterns — women's formula factors in hip circumference because fat distribution differs from men's, where waist and neck alone were found to be sufficient predictors.
Where exactly should I measure my neck and waist?
Neck: just below the larynx (Adam's apple), tape sloping slightly downward at the front. Waist: at the navel for men, at the narrowest point for women. Measure snug against the skin without compressing it, for the most accurate reading.
Why does the formula need log10?
The Navy method's coefficients were statistically fitted to circumference and body-fat data using logarithms of the measurements, which produced a better-fitting curve than a simple linear formula — it's a product of how the original research was modeled, not something you need to compute by hand.
Is my numbers uploaded anywhere?
No — Calculadora de Gordura Corporal runs entirely in your browser using JavaScript/WebAssembly. Your numbers is never sent to a server.